"Which" 350 is the One?

[Kilo19]

Ohhhhhhhhhh ( light bulb turned on )


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[Scooter402]

The new heads are way better than the camel bump ones and can be used on the old blocks. A buddy of mine has a 4bolt block with the new heads in a '67 RS. It's real nasty.

I'll have to agree here, too. The camel humps were the bread and butter back in the day, and as far as old school factory heads, they were always the best.

Today's Vortec heads do have their limitations, but they can also be made into great heads. Any head (well, almost...) can be made great if you know what you're doing with a die grinder, some carbide bits, and some polishing wheels. Porting your own heads is gratifying, especially when you feel the gains in power you created...On the other hand, they can easily go in the compete opposite direction...Ask me how I know. It took some "practice heads" to get a good thing going.

There are also many aftermarket heads that can be had on the cheap that perform very well. Look up "SBC heads" on eBay, and you'll come up with many. I don't know they still do, but Terry Rosebush Motorsports used to sell blem Dart Iron Eagle heads bare on eBay for less than $400 a pair. I got a great set of those in the 230cc variety with 2.08 intake valves and 1.60 exhaust. Those I would only reccomend if you are racing, though. 2.02's would be plenty big for a street/trail 350.

 

[tarry99]

Hi all,

What have the folks who put in 350's used?

So I've heard and read that installing a Chevy Small Block 350 is the better way to upgrade from my old i6 to V8 power, and not going with the AMC 304.

However, when I called my local used engine shop nearby they asked 'Which 350 are you looking for?'

I was stunned because it hadn't occurred to me that they were different.

I'd like a carburetor simply because converting the jeep over to Fuel Injection seems to me to be as likely as organizing a 3 stage satellite launch from my garage. Its a giant, scary question mark in my head. I'll cross that hurtle if I must but based on the Shop's inventory it looks like I'm going Fuel Injection.

So, do I want a Pick up engine? Malibu? Police interceptor. . .. mmmmm. Impala? so on and so on.

LtBest...............Before you set out on a rebuilt motor, you should price all the necessary parts and machine work needed to make it right. Also regarding used I'm not a big fan of sticking an unknown motor in anything and then having to pull it out at a later date............Once you have the rebuild cost in hand take a look at the GM crate motors programs available from GM.......cheap compared to some rebuilds , guaranteed and you can just about find anything performance & price wise.

And as far as those old Hump back casting GM heads those guys mentioned they are really showing off there age (LOL).........I think the first set came out around 1962 in a Corvette with a 327 inch FI motor & 2.02 Intake valves. Great stuff for the day not so now.

 

[Barry2]

 

[CJ]

Showing off my age! Lol , yep I'm 49 going on 50... I used to port my heads using a shop vac! Those were the days!

As for the AMC 304 question, AMC heads flow great, the dog leg exhaust ports are great, unfortunately the AMC 304 is Limited by the valve size due to the bore, for a 5 liter engine it can be setup to scream (if you do the oiling mods).

 

[Scooter402]

Wow, is that yours? Jealous!

Showing off my age! Lol , yep I'm 49 going on 50... I used to port my heads using a shop vac! Those were the days!

As for the 304 question, AMC heads flow great, the dog leg exhaust ports are great, unfortunately the 304 is limited by the valve size due to the bore, for a 5 liter engine it can be setup to scream (if you do the oiling mods).

Well, I guess I'm just showing off who I learned from...because I'm not that old...Lol I'm a week out of 30. But if it's any consolation, I have been working on engines (and transmissions, and differentials, and transfer cases, and and and...Lol) with my dad literally since I was old enough to hold a wrench.

Just to throw another monkey on your back...the AMC 360s can be good, torquey engines too. I had one in my CJ before the 383 that I put in it before the 402 I've got now. Good bit more grunt than a AMC 304 . That, and it will bolt directly to your existing bellhousing. Just a thought...

 

[Kane]

The lates 70's truck blocks have the 4 bolts mains and a more desirable high tin percentage. these are considered stronger and hold a more consistant bore than other blocks. I used one from a 1978 truck for my build. I ran flat top forged pistons, Summit stage II con rods, Edelbrock aluminum heads, a decent cam and full MSD ignition system. I have a carb on it but the motor pulls like a freight train. I may end up with a fuel injection system on it for my other jeep build since I know it will handle any abuse I give it.

 

[tarry99]

Supercharger Huh? I guess everyone has got there need for Speed.
Off road 200 HP and a low crawl ratio, On road maybe a little more HP and some taller gears...........a Quick 6 second trip to the supermarket? and I'm in my other Willys a 1940 coupe that is...........Like I said everyone has got there need for Speed!

 

[Scooter402]

The lates 70's truck blocks have the 4 bolts mains and a more desirable high tin percentage. these are considered stronger and hold a more consistant bore than other blocks. I used one from a 1978 truck for my build. I ran flat top forged pistons, Summit stage II con rods, Edelbrock aluminum heads, a decent cam and full MSD ignition system. I have a carb on it but the motor pulls like a freight train. I may end up with a fuel injection system on it for my other jeep build since I know it will handle any abuse I give it.

I may be mistaken, but I thought it was the high nickel content that made the stronger blocks with less core shift. At any rate, these we are speaking of had both -- higher nickel and tin.

The casting number (if you're looking for an older 2-piece rear main seal) you would be looking for is 3970010 -- more often than not, these are a 4 bolt main 350. I did find one that wasn't, though...that was the 350 I put in my first Jeep. It was actually a 2 bolt main block. I didn't find that out until I got it back home. Guy at the junk yard told me he had this -010 350 block, said it was 4 bolt main, sold it to me for $200 cash. Got home and found 2 bolt mains...Oh, well. I wasn't racing the motor, anyway. I replaced the crank, pistons, rods, cam, heads, intake, everything inside and out. Come to find out years later that the 3970010 block was also used in some 327 applications. Highly likely that's what the engine I had originally was...and I threw the crank in the trash.

Tarry99 -- Nice Willys! I love the 1940-41 Willys, especially the trucks...Too bad one can't be had for less than a small fortune...

 

[Kane]

Yeah you are right on both accounts. I made a quick post.

 

[Tinman22]

Sbc blocks are not all created equal. Early blocks had leak prone rear main seals. Gen 2 blocks had 1 piece rear mains but weren't cast especially well and on and on and on for ever. answering your question though is easy,1996-2003 gen3 small blocks were by far the best built . Look for a 97-98 vortec truck motor . Vortec heads will outflow the fabled 2.02 heads any day and the valve covers don't leak. Two different vortec heads We're used the 906 and the 062, the difference is valve Seats ,906s flow a bit better and resist heat better and used mostly in hd trucks. Steel cranks are common in these years and are not as crack prone as the early steel cranks. The blocks had a little better oiling system and a one piecr rear main seal that dosent leak.Most had roller lifter/cams but not all , so if you want roller make sure it is a roller motor . If you rebuild it be sure to use steel shim head gaskets .015 compared to much thicker composit gasket usually around .040 it helps keep the compression up. shim gaskets are what came on them. Also 4 bolt or 2 bolt is really irrelevant any more at power levels below 350 either are good. At 350 to 475 a 2 bolt using arp bolts Is plenty strong and 4 bolt above that. If a re-ring job is on the list it may be cheaper to buy pistons ring sets are metric and around 120.00 for a decent set . A set of hyperutectic claimer pistons with rings for the same price makes more sense. And on and on and on I've got 9 of them that have got to go! Bring a truck I'll give you one for free.

 

[Barry2]

I have a SBC in my 74 CJ5 but I managed to post the wrong pic. That pic is of my 2000 TJ street only , my CJ for wheelin' and a 99 XJ for getting the groceries.

 

[LtBest]

LtBest...............Before you set out on a rebuilt motor, you should price all the necessary parts and machine work needed to make it right. Also regarding used I'm not a big fan of sticking an unknown motor in anything and then having to pull it out at a later date............Once you have the rebuild cost in hand take a look at the GM crate motors programs available from GM.......cheap compared to some rebuilds , guaranteed and you can just about find anything performance & price wise.

And as far as those old Hump back casting GM heads those guys mentioned they are really showing off there age (LOL).........I think the first set came out around 1962 in a Corvette with a 327 inch FI motor & 2.02 Intake valves. Great stuff for the day not so now.

I think I will find this exceptionally good advice. Without a machine shop in my basement or a handful of friends with machine shops, we may head down the 'crate' route.

 

[tarry99]

I think I will find this exceptionally good advice. Without a machine shop in my basement or a handful of friends with machine shops, we may head down the 'crate' route.

Lt............Summit & Jegs on line sell the GM programS and some but not all GM dealer parts departments also do. Do some shopping among the dealers.....

Good Luck on your project!

 

[007]

I built one of those 3970010 blocks with flat-top pistons, an Edelbrock Performer cam and intake and an Edelbock 600CFM carb. Used Crane stamped steel roller rockers and it was all the engine a truck would need. Plenty of torque and a smooth power band. Mine came out of a 78 Chevy Big10 Truck. There's millions of them laying around and most have heads with the right valves in them, but have them magnafluxed... ;-)

 

[Tinman22]

Low mileage 96-03 roller vortec 350's can be had for under 500.00 range in hp from 255-350 swap intake manifold too an air gap. Drop in an hei dizzy top it with a 600 truck avenger and run it.